Abstract
Although microwave-assisted thermal sterilisation (MATS) held great potential to sterilise ready-to-eat (RTE) products compared with traditional retort sterilisation, the quality improvement effect of MATS treatment on shelf-stable RTE products has not been extensively studied. This study was performed to evaluate the efficacy and applicability of MATS combined with olive oil vacuum impregnation against lipid oxidation and microbial growth in RTE Pacific saury during storage. MATS combined with olive oil vacuum impregnation (MTSO) effectively reduced processing time (by 57%) compared to retort-treated RTE Pacific saury at the same thermal lethality value. The lower cooking loss (6.19%) and colour damage indicated that MTSO enhanced water retention and the stability of tissue structure compared to retort-treated group (9.88%) or no olive oil group (7.11%). Lipid oxidation and protein degradation were effectively inhibited in MATS groups compared to retort-treated ones during storage; such effect was more effective in olive oil impregnated group. Likewise, microbial activity and electronic sensory evaluations showed that the shelf life of MTSO group was extended by 1 week compared to retort-treated groups. Overall, MTSO had considerable industrial potential to yield RET Pacific saury and even RTE products with better quality attributes than retort-treated ones.